The BBC has launched a nationwide health campaign to give people the facts about obesity - a serious medical issue - and to help them lead leaner, fitter lives. BBC News Online has been speaking to Lord Lawson about his approach to successful dieting:

Nigel Lawson was the man who made Britain boom in the 1980s. As Margaret Thatcher's Chancellor of the Exchequer, he led the country through a period of high growth and low inflation.

The political cartoonists loved him because he was fat - 17 stone - an easy victim for their pens. But Nigel, now Lord, Lawson shocked the satirists and the nation by going on a hugely successful diet. So great was the response to his achievement, that his book, the Nigel Lawson Diet Book, about how he lost five stone, became a best seller.

"I was certainly a fat man. It came up gradually, and by the time I was Chancellor, certainly, that was the thing the cartoonists seized on; that was part of the image - no doubt about it," he recalls.

A rich meal

The Sunday Times political cartoonist, Gerald Scarfe, caricatured Lawson many times. He had no scruples about portraying a very public figure in a very unflattering way.

Nigel Lawson was an easy target for the satirists

"He was wonderful to draw because he was almost an eighteenth century figure. There's a drawing of him in 1988 when he produced a budget and he's scoffing a chicken leg, and in front of him there's a piece of roast beef and some giant cakes and so forth, and it's called A Very Rich Meal."

Gerald Scarfe has many others in his collection. One, which is titled Fighting Inflation, has an overblown Lawson floating off into the distance.

Surprisingly, these very personal attacks had little effect on the Conservative politician.

"It didn't upset me," Lord Lawson says now. "Maybe it should have done because I think the cartoonists' exaggeration may have been slightly annoying, but I had far more annoying things than that to contend with so I didn't really worry about it."

A pressing problem

When he left frontline politics, however, the former Chancellor was determined to do something about his size.

"The trigger was nothing to do with vanity. It was because I found I suddenly had a bad knee which the doctor was able to deal with satisfactory - I'm glad to say. But what he did say was that 'your knees are having to bear to much weight and unless you reduce the amount of weight that your poor old knees are having to carry, then as you get older, this is going to come back and is going to get steadily worse'".

There was nothing very unusual in his diet. He realised his basic problem was over-consumption. He cut down and he cut out a lot of dairy products and other fatty foods. He also started to drink fizzy diet drinks instead of alcohol.

Lord Lawson claims it was relatively easy: "What I am saying, very simply, is that if, for whatever reason of your own choosing, you wish to lose weight, here is what one man found to be a very effective and relatively painless way of doing it."

BBC Local Radio is running a series of information items as part of the Taking Shape campaign. For example, the network features the new healthy living centres being promoted by the government. The centres, funded from National Lottery money to the tune of £300m, will help address some of the inequalities in healthcare that are experienced by those who live in deprived areas.

You can also call the BBC ActionLine on 0800 888806. There is a free pack of very useful information, which includes tips on how to establish a healthier eating pattern, some specially developed recipes and a free fridge magnet to help you stay on course.

Some facts and figures about obesity:

Obesity is rising rapidly throughout the world. In the UK during the 1980s the number of obese people doubled. In Britain today, half the adult population are overweight and almost one in five men and women are clinically obese.

As a rough guide, men with a waist circumference greater than 102 cm (40 inches) and women with a waist circumference of 88 cm (35 inches) would benefit from losing weight.

Obesity is a major contributing factor to heart disease, hypertension, stroke, diabetes, certain types of cancer, gallstones, osteoarthritis and infertility.

Obesity tends to run in families. Children with two obese parents have about a 70% risk of becoming obese. However, if both parents are lean, the chances are reduced to 20% This is partly due to genetic factors, but families usually share the same diet, lifestyle and cultural influences and these habits tend to continue into later life.

Trying to cut down on fat in the diet is a great help to anyone trying to lose weight. Fat contains twice as many calories per gram as protein or carbohydrate. Fat does not seem to promote the same "stop eating" signals compared to carbohydrate protein-rich foods. This means we tend to eat even more fat calories before we become satisfied.

We should all try to become more active. Strolling for 20 minutes each day at a leisurely pace expends additional energy equivalent to two kilograms of fat per year.